The invention is directed to a composition for use in the repair and healing of osseous tissue. The composition contains particulate bone including allogenic, autogenic, or xenogenic bone; cancellous, corticocancellous, and/or cortical bone; and one or more semi-synthetic polymers including for example one or more cellulosics. The composition may also optionally contain one or more pharmaceutically active agents. The composition can be formulated as a gel, putty, paste, cake, or solid.
The use of bone material derived from demineralized allogenic or xenogenic bone in surgical repair of bone defects, is known. Bone material contains substances for example, bone morphogenic protein, which induce bone regeneration at a defect site. U.S. Pat. Nos. 5,405,390; 5,314,476; 5,284,655; 5,510,396; 4,394,370; and 4,472,840, disclose compositions containing demineralized bone powder. These prior art compositions are problematic in that they are difficult to handle during surgery or implantation; and wash away during lavage (i.e. does not remain at the implant site). The inventive composition exhibits excellent properties, does not wash away during surgical lavage; and can be formulated as a gel, a putty, paste, or solid, depending on the characteristics desired for the particular application.
The invention is directed to a bone matrix composition, including bone and one or more semi-synthetic polymers.
The invention is directed to a bone matrix composition where the one or more semi-synthetic polymers include one or more water soluble semi-synthetic polymers.
The invention is yet further directed to a bone matrix composition where the bone is allogenic bone, autogenic bone, or xenogenic bone.
The invention is directed to a bone matrix composition where the one or more semi-synthetic polymers are non-liquid.
The invention is also directed to a bone matrix composition where the composition is in the form of a gel, a putty, a paste, a cake, or a solid.
The invention is directed to a bone matrix composition, including one or more of the following: ground demineralized bone, ground mineralized bone, and ground partially mineralized bone, and one or more semi-synthetic polymers.
The invention is further directed to a bone matrix composition, including one or more of the following: ground demineralized bone, ground mineralized bone, and ground partially mineralized bone, with the bone present in an amount of from 10 wt % to about 85 wt %, preferably from about 20 wt % to about 75 wt %, and more preferably from about 30 wt % to about 70 wt %, and most preferably, from about 35 wt % to about 70 wt %, and including one or more semi-synthetic polymers.
The invention is also directed to a bone matrix composition where the composition is a gel, and the gel includes from about 15 wt % ground demineralized bone to about less than 60 wt % ground demineralized bone.
The invention is also directed to a bone matrix composition where the composition is a putty, and the putty includes from about 30 wt % ground demineralized bone to about 80 wt % ground demineralized bone.
The invention is further directed to a bone matrix composition, including ground, demineralized, xenograft bone and one or more semi-synthetic polymers.
The invention is directed to a bone matrix composition where the composition is a gel, which includes ground demineralized bone present in an amount of from 15 wt % to about less than 60 wt % and one or more cellulosics.
The invention is also directed to a bone matrix composition including one or more plasticizers.
The invention is also directed to a reconstructed bone graft including a bone matrix composition containing demineralized and/or partially demineralized bone and one or more semi-synthetic polymers, which composition has been remineralized.
The invention is directed to a bone matrix composition where the bone is demineralized and/or mineralized and/or partially demineralized cancellous bone.
The invention is directed to a bone matrix composition where the bone is demineralized and/or mineralized and/or partially demineralized, cancellous bone and/or cortical bone and/or corticocancellous bone.
The invention is also directed to a composition including demineralized cortical bone and one or more semi-synthetic polymers, in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is further directed to a bone matrix composition where the cellulosic and/or semi-synthetic polymer, are non-liquid.
The invention is further directed to a composition including demineralized cancellous bone and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including mineralized cancellous bone and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including mineralized cortical bone and one or more semi-synthetic polymers in a putty, a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including surface demineralized cortical bone and one or more semi-synthetic polymers, in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including demineralized cancellous bone and cortical bone (mineralized and/or demineralized and/or partially demineralized and/or surface demineralized) and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is also directed to a composition including partially demineralized cortical bone and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is further directed to a composition including partially demineralized cancellous bone and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including partially demineralized cortical bone and partially demineralized cancellous bone and one or more semi-synthetic polymers in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is directed to a composition including partially demineralized cortical and/or cancellous bone; and mineralized and/or demineralized, cortical and/or cancellous bone; and one or more semi-synthetic polymers; in a gel, a putty, a paste, a cake, or a solid formulation.
The invention is further directed to a method for making a bone matrix composition including the steps of mixing bone with one or more dry semi-synthetic polymers to form a dry mixture; and adding water to the dry mixture to form a gelled composition.
The invention is further directed to a method for making a solid composition including the steps of mixing bone with one or more non-liquid semi-synthetic polymers to form a dry mixture; adding water to the dry mixture to form a gelled composition; and removing moisture from the gelled composition, for example using freeze-drying and/or subjecting the gelled composition to negative pressure or positive pressure, to form a solid composition.
The invention is also directed to a method for making a solid composition including the step of subjecting the gelled composition to positive pressure or negative pressure.
The invention is also directed to a method for making a solid composition where moisture is removed from the gelled composition by freeze drying the gelled composition.
The invention is also directed to a method for making a bone matrix composition, where the composition is produced under sterile conditions.
The invention is directed to a method for making a bone matrix composition, including sterilizing the composition produced using radiation.
The invention is directed to a bone matrix composition where one or more water soluble semi-synthetic polymers include one or more cellulosics.
The invention is further directed to a bone matrix composition where the one or more cellulosics include one or more of the following: carboxy methyl cellulose; hydroxy propyl cellulose; hydroxy ethyl cellulose; and methyl cellulose.
I. Definitions
The below definitions serve to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms.
Allogenic. By the term xe2x80x9callogenicxe2x80x9d is intended tissue including bone tissue having a different gene constitution than the intended recipient, but being from the same species.
Autogenic. By the term xe2x80x9cautogenicxe2x80x9d is intended tissue including bone tissue from the intended recipients own body.
Biocompatible. By the term xe2x80x9cbiocompatiblexe2x80x9d is intended for the purposes of the invention, any material which does not provoke an adverse response in a patient. For example, a suitable biocompatible material when introduced into a patient does not itself provoke a significant immune response, and is not toxic to the patient.
Bone. By the term xe2x80x9cbonexe2x80x9d is intended any bone including allograft bone, autograft bone and xenograft bone, and includes bone in any form including but not limited to: mineralized and/or demineralized bone and/or partially demineralized bone, and cancellous and/or cortical bone and/or corticocancellous, where the bone is in a form including but not limited to: particulate bone, ground bone including but not limited to bone in the particle size range of 125xcexc to about 1000xcexc, preferably about 250xcexc to 710xcexc, bone chips, cut bone pieces including cubes, iliac crest wedges, Cloward dowels, or strips, and essentially intact bone including the patient""s own bone in the patients body, and bone including for example: the femur, tibia, ilia, humorous, radius, ulna, ribs, whole vertebrae, mandibula, and any segment thereof.
Bone defect site. By the term xe2x80x9cbone defect sitexe2x80x9d is intended for the purposes of the invention, any site in an animal including a human, where the inducement of bone growth and/or repair, is desired.
Carboxy methyl cellulose. (CMC) By the term xe2x80x9ccarboxy methyl cellulosexe2x80x9d is intended a semi-synthetic polymer which is water soluble, and is an acid ether derivative of cellulose, where carboxy methyl groups are substituted on the glucose units of the cellulose chain through an ether linkage ( carboxy methyl groups are substituted for the hydroxyl groups along the carbon chain).
Cellulosic. By the term xe2x80x9ccellulosicxe2x80x9d is intended for the purposes of the invention, any semi-synthetic polymer that is a derivative of cellulose, including but not limited to: methyl cellulose; carboxy methyl cellulose; hydroxy propyl cellulose; and hydroxy ethyl cellulose.
Demineralized Bone. By the term xe2x80x9cdemineralized bonexe2x80x9d is intended for the purposes of this invention, any bone including cortical and/or cancellous bone, from any source including autogenic, allogenic and/or xenogenic bone, demineralized to contain less than about 5 wt % residual calcium.
Dry Bone. By the term xe2x80x9cdryxe2x80x9d or xe2x80x9cdriedxe2x80x9d bone is intended particulate bone that has been freeze dried or air dried and has a density of about 0.443.
Essentially Free From. By the term xe2x80x9cessentially free fromxe2x80x9d is intended bone where the material removed (i.e., bone marrow, viral, fungal, and/or bacterial particles) from the bone is not detectable using detection means known in the art to which the invention pertains at the time of filing of this application.
Ether Derivative of a Polysaccharide. By the term xe2x80x9cether derivative of a polysaccharidexe2x80x9d is intended those derivatives that are also semi-synthetic polymers, and includes acid ether derivatives of polysaccharides including for example, cellulosics including for example, methyl cellulose, carboxy methyl cellulose, hydroxy propyl cellulose, and hydroxy ethyl cellulose.
Flowable. By the term xe2x80x9cflowablexe2x80x9d is intended a deformable and shape sustaining composition that includes a gel, putty, paste, solid, and a cake.
Gel. By the term xe2x80x9cgelxe2x80x9d is intended for the purposes of the invention a hydrogel which is a colloid in which the particles are in the external or dispersion phase and water in the internal or dispersed phase. A gel is an intermediate form of matter between a liquid and a solid. The present gels are sufficiently viscous to be extruded through a syringe, and are shape-sustaining and deformable. The gel contains less than 60 wt % bone; and preferably contains about 20 wt % bone to about 65 wt % bone; more preferably from about 25 wt % bone to about 60 wt % bone; even more preferably from about 30 wt % bone to about 55 wt % bone; and most preferably from about 45 wt % to about 49 wt %. Preferably the bone used is demineralized cortical and /or cancellous bone, and is autogenic, allogenic and/or xenogenic bone.
Osteoconductive. By the term xe2x80x9costeoconductivexe2x80x9d is intended for the purposes of the invention, the ability of a substance to support or conduct bone growth.
Osteoinductive. By the term xe2x80x9costeoinductivexe2x80x9d is intended for the purposes of the invention, the ability of a substance to induce bone growth.
Patient. By the term xe2x80x9cpatientxe2x80x9d is intended for the purposes of the invention, an animal including a human, who is subject to medical treatment.
Partially Demineralized Bone. By the term xe2x80x9cpartially demineralized bonexe2x80x9d is intended, any bone including cortical and/or cancellous bone, from any source including autogenic, allogenic and/or xenogenic bone, demineralized to contain less residual calcium than is present in intact natural bone (that is, demineralized to contain less than about 30 wt % residual calcium) and preferably demineralized to contain more than about 5 wt % residual calcium and less than about 30 wt % residual calcium.
Pharmaceutically Active Agent. By the term xe2x80x9cpharmaceutically active agentxe2x80x9d is intended, any medically useful substance including any therapeutically beneficial substance, including but not limited to: viricides; microbicides; antibiotics; amino acids; peptides; vitamins; co-factors for protein synthesis; hormones including growth hormones; endocrine tissue; living cells including for example: stem cells, chondrocytes, bone marrow cells, and parenchymal cells; synthesizers; enzymes; angiogenic drugs including nicotine and nicotinic acid; biocompatible surface active agents; antigenic agents; cytoskeletal agents; growth factors including but not limited to: transforming growth factor, and insulin like growth factor; antitumor agents; immuno-suppressants; and permeation enhancers.
Plasticizer. By the term xe2x80x9cplasticizerxe2x80x9d is intended for the purposes of the invention, any biocompatible compounds which are soluble in water and can easily displace/replace water at the molecular level and preferably have a low molecular weight such that the plasticizer fits into the spaces available to water within the hydrated molecular structure of the bone or soft tissue. Suitable plasticizers for use in the invention include but are not limited to: polar and non-polar plasticizers including but not limited to: mono-di or -tri esters of citric acid, phthalic acid, sebacic acid, azaleic acid, adipic acid, trimeilitic acid, and epoxidized soya oils; glycerol; adonitol; sorbitol; ribitol; galactitol; D-galactose; 1,3-dihydroxypropanol; ethylene glycol; tirethylene glycol; propylene glycol; glucose; sucrose; mannitol; xylitol; meso-erythritol; adipic acid; proline; hydroxyproline or similar water-soluble small molecular weight solutes Plasticizers are preferred for use at concentration in the range of from 0.1M to 3.0M and in an amount of from 3.0 to 50.0 wt %, preferably 20.0 to 40.0 wt %, and most preferably about 35.0 wt % to about 40 wt %.
Polysaccharide. By the term xe2x80x9cpolysaccharidexe2x80x9d is intended for the purposes of the invention, any combination of nine or more monosaccharides, linked together by glycosidic bonds.
Putty Composition. By the term xe2x80x9cputty compositionxe2x80x9d is intended for the purposes of the invention a hydrogel which is a colloid in which the particles are in the external or dispersion phase and water in the internal or dispersed phase. The present putty""s are moldable and shape sustaining. The putty contains greater than 30 wt %, preferably contains about 40 wt % bone to about 50 wt % bone; more preferably from about 45 wt % bone to about 49 wt % bone; and even more preferably from about 44 wt % to about 48 wt % bone. Preferably the bone used is demineralized cortical and/or cancellous bone, and is autogenic, allogenic and/or xenogenic bone.
Semi-synthetic polymer. By the term xe2x80x9csemi-synthetic polymer, is intended any polymer which is preferably water soluble of the semi-synthetic type, and being a macromolecule formed by the chemical union of five or more identical combining units called monomers, and includes chemically treated natural polymers including but not limited to: cellulosics including for example rayon, methyl cellulose, carboxy methyl cellulose, hydroxy propyl cellulose, hydroxy ethyl cellulose, cellulose acetate, and other cellulose ethers; and modified starches including for example acetates and ethers including for example, starch acetate. Water-soluble ethers are preferred semi-synthetic polymers. Less water-soluble semi-synthetic polymers may also be used, for example with a biocompatible solvent that is miscible in water. Such polymers include cellulose plastics including for example cellulose acetate phthalate.
Thixotropic Agent. By the term xe2x80x9cthixotropic agentxe2x80x9d is intended any substance pertaining to or characterized by thixotropy. Thixotropy is a reclotting phenomenon; it is the property of certain gels of becoming less viscous when shaken or subjected to shearing forces and returning to the original viscosity upon standing; a characteristic of a system exhibiting a decrease in viscosity with an increase in the rate of shear, usually a function of time. Suitable thixotropic agents for use in the invention include but are not limited to the following: carboxyl methyl cellulose; pectin; and methyl cellulose.
Wet bone. By the term xe2x80x9cwet bonexe2x80x9d is intended bone that is wet; damp; or freeze-dried, wet, and then centrifuged; and such bone has a density of about 0.828.
Xenogenic. By the term xe2x80x9cxenogenicxe2x80x9d is intended for the purposes of this invention, tissue including bone tissue that is heterologous, with respect to the intended recipient, i.e. the donor and recipient are from widely separated species. For example, if the intended recipient is human, xenogenic tissue would be tissue from a species other than human.
II. The Composition
The invention is a bone matrix composition that contains bone and one or more semi-synthetic polymers. The composition can be formulated as a gel, a putty, a paste, a cake or a solid composition.
Preferred formulations of the inventive composition include: (a) a composition including demineralized cortical bone and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; (b) a composition including demineralized cancellous bone and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; (c) a composition including demineralized cancellous and demineralized cortical bone, and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; (d) a composition including partially demineralized cortical bone and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; (e) a composition including partially demineralized cancellous bone and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; (f) a composition including partially demineralized cortical bone and partially demineralized cancellous bone and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation; and (g) a composition including partially demineralized cortical and/or cancellous bone, and mineralized and/or demineralized, cortical and/or cancellous bone, and one or more semi-synthetic polymers in a putty, gel, paste, cake or solid formulation.
Preferred semi-synthetic polymers include water-soluble semi-synthetic polymers. Preferred water-soluble, semi-synthetic polymers include cellulosics. Preferred cellulosics include methyl cellulose; carboxy methyl cellulose; hydroxy ethyl cellulose; and hydroxy propyl cellulose.
Preferred formulations of the inventive gel, include: one or more semi-synthetic polymers in an amount of from 0.5 wt % to about 4.0 wt %, preferably from about 1.0 wt % to about 3.5 wt %, more preferably from about 1.5 wt % to about 3.2 wt %, and most preferably from about 2.0 wt % to about 2.9 wt %. The use of demineralized bone is preferred and is present in an amount of from 30.0 to 55.0 wt %, preferably from about 40.0 wt % to about 50.0 wt %, more preferably from about 45.0 wt % to about 49.0 wt %, and most preferably about 47.0 wt %. Water is present in an amount of from about 40.0 wt % to about 60.0 wt %, preferably from about 45.0 wt % to about 55.0 wt %, most preferably from about 48.0 wt % to about 53.0 wt %, and most preferably about 51.0 wt %. Specific preferred gel formulations include formulations containing from about 2.0 wt % to about 2.9 wt % of a cellulosic, preferably carboxy methyl cellulose; about 47.0 wt % demineralized bone; and about 51.0 wt % water.
Preferred formulations of the inventive paste, include: one or more semi-synthetic polymers in an amount of from 2.5 wt % to about 6.0 wt %, preferably from about 3.0 wt % to about 4.5 wt %, more preferably from about 3.4 wt % to about 4.2 wt %, and most preferably about 3.8 wt %. The use of demineralized bone is preferred and is present in an amount of from 30.0 to 55.0 wt %, preferably from about 40.0 wt % to about 50.0 wt %, more preferably from about 45.0 wt % to about 49.0 wt %, and most preferably about 47.0 wt %. Water is present in an amount of from about 40.0 wt % to about 60.0 wt %, preferably from about 45.0 wt % to about 55.0 wt %, most preferably from about 48.0 wt % to about 52.0 wt %, and most preferably about 50.0 wt %. Specific preferred paste formulations include formulations containing about 3.8 wt % of a cellulosic, preferably carboxy methyl cellulose; about 47.0 wt % demineralized bone; and about 50.0 wt % water.
Preferred formulations of the inventive putty, include: one or more semi-synthetic polymers in an amount of from 6.0 wt % to about 13.0 wt %, preferably from about 7.0 wt % to about 12.0 wt %, more preferably from about 7.5 wt % to about 11.0 wt %, and most preferably from about 8.0 wt % to about 9.7 wt %. The use of demineralized bone is preferred and is present in an amount of from 30.0 to 55.0 wt %, preferably from about 40.0 wt % to about 50.0 wt %, more preferably from about 45.0 wt % to about 49.0 wt %, and most preferably about 44.0 wt % to about 48.0 wt %. Water is present in an amount of from about 35.0 wt % to about 55.0 wt %, preferably from about 40.0 wt % to about 50.0 wt %, most preferably from about 42.0 wt % to about 48.0 wt %, and most preferably from about 44.0 wt % to about 46.0 wt %. Specific preferred putty formulations include formulations containing from about 8.0 wt % to about 9.7 wt % of a cellulosic, preferably carboxy methyl cellulose; from about 44.0 wt % to about 48.0 wt % demineralized bone; and from about 44.0 wt % to about 46.0 wt % water.
Preferred formulations of the inventive cake, include: one or more semi-synthetic polymers in an amount of from 8.0 wt % to about 16.0 wt %, preferably from about 9.0 wt % to about 15.0 wt %, more preferably from about 10.0 wt % to about 14.0 wt %, and most preferably about 12.0 wt %. The use of demineralized bone is preferred and is present in an amount of from 60.0 to 90.0 wt %, preferably from about 65.0 wt % to about 85.0 wt %, more preferably from about 70.0 wt % to about 80.0 wt %, and most preferably about 75.0 wt %. Water is present in an amount of from about 5.0 wt % to about 21.0 wt %, preferably from about 8.0 wt % to about 19.0 wt %, most preferably from about 10.0 wt % to about 15.0 wt %, and most preferably about 13.0 wt %. Specific preferred cake formulations include formulations containing about 12.0 wt % of a cellulosic, preferably carboxy methyl cellulose; about 75.0 wt % demineralized bone; and about 13.0 wt % water.
The above recited weight percent amounts reported for xe2x80x9cbonexe2x80x9d are based on wet centrifuged bone having a density of about 0.828. The weight percent for damp or dry bone can be calculated based on the density of the damp or dry bone samples, and such calculation can be readily performed by one of ordinary skill in the art without undue experimentation.
III. Methods of Making the Bone Matrix Composition
The inventive composition including a gel, putty, paste, cake, and solid formulations are all initially prepared by first combining the non-liquid semi-synthetic polymer with the bone which bone is preferably demineralized bone in a particulate form where the bone is dry or wet. Thereafter, the non-liquid particulate bone/polymer combination is mixed with water to form a bone matrix composition. Preparation of the composition may be carried out sterilely or the composition may be sterilized after packaging using irradiation, for example e-beam sterilization.
The composition may optionally contain one or more additional substances including but not limited to: one or more thixotropic agents, one or more plasticizers, one or more therapeutically beneficial substances and/or pharmaceutically active substances, including but not limited to growth factors including bone growth factors including for example bone morphogenic protein. Suitable bone material includes freeze-dried bone, air-dried bone; and/or wet bone including for example wet centrifuged bone, where the residual moisture content of the bone is preferably less than 8.0 %, more preferably less than 7.0 % and most preferably less than 6.0 % residual moisture. The bone material is preferably particulate bone. Suitable bone material includes demineralized bone, and/or partially demineralized bone, and/or mineralized bone, where the bone is cortical bone, and/or corticocancellous bone, and/or cancellous bone.
Optional substances including any one or more of a pharmaceutically active agent, a therapeutically beneficial substance, a thixotropic agent, and a plasticizer, may be added to the composition before, during, or after, the addition of bone to the non-liquid particulate mixture of bone and polymer.
The composition may be packaged and sterilized for example using irradiation, and distributed. For example, the gel formulation may be sterilely packaged in a syringe, and the putty, paste, cake, or solid, formulation may be sterilely packaged in a jar or blister package, and then sterilized.
IV. Use of the Bone Matrix Composition
The compositions are useful for repairing bone defects arising from any cause including congenital defects and trauma induced defects.
The compositions are suitable for use in dental applications, neurosurgical, and orthopaedic applications, as well as in any application where the repair of a bone defect, including a bone void, is desired.